Machine tool transmission and control



Dec. 31,' 135. F. A. PARSONS MACHINE TOOL TRANSMISSION AND CONTROL Filed Dec.

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F. A. PARSONS MACHINE TOOL TRANSMISSION AND CONTROL;

Filed Dec. 12, 1930 6 Sheets-Sheet 2 Dec. 31, 1935. F, A. PARSONS 2,@26,247

MACHINE TOOL TRANSMISSION AND CONTROL Filed Dec. 12, 1930 6 Sheets-Sheet 3 CA 577 N5 Pf-FE55UR5 CONTROL v 72741 594705 H/Y N D CON 77PM.

7 5/7 PE F J TUFE 1386- 1935- F. A. PARSONS I MACHINE TOOL TRANSMISSION AND CONTROL 6 Shets-Sheet 4 Filed Dec. 12, 1930" 5 8 b 4 3B a #A/ m u. .w F- |i| \\i\\r W. 4 w m 5 v Wm 0% 6 K E 7 L W x L 7 2 p w .M. Q 7 Q m m Dec. 31, 1935.

F. A. PARSONS MACHINE TOOL TRANSMISSION AND CONTROL Filed Dec. 12, 1930 6 Sheets-Sheet 5 Dec. 31, 1935. F. A. PAR SONS 2,026,247

MACHINE TOOL" TRANSMISSION AND CONTROL Filed Dec. 12, 1930 e Sheets-Sheetfi Patented Dec. 31, 1935 UNITED STATES PATENT OFFICE MACHINE TOOL TRANSMISSION This invention relates to transmission and NTROL Fred A. Parsons, Milwaukee, Wis., assignor to livgrney & Trecker Corporation, West Allis,

Application December 12, 1930, Serial No. 501,889

24 Claims.

control mechanism for machine tools and more especially to such a mechanism in a form particularly adapted for milling machines.

A purpose of the invention is to provide an improved transmission and an improved control therefor and an improved combination of such transmission and control with a machine tool, more particularly for the relative movement of the work and cutter in a milling machine.

Another purpose is to provide improvements in a transmissionwhich is in part fluid operated, and an improved control thereof, particularly of the fluid operated portion.

Another purpose is to provide improvements in a transmission having a fluid operated portion and in control means for maintaining the rate of a member driven therefrom substantially constant in spite of variations in fluid leakage caused by variations in load resistance or fluid characteristics. 4

Another purpose is to provide a machine tool including an improved hydraulic transmission capable of various settings or adjustments for-- driving a part of the machine tool at'various' pre-selected rates and means for maintaining.

a selected rate constant in spite of variations in resistance to travel of such part orin spite of changes in temperature and consequent changes in properties of the working fiuid or in spite of changes in both resistance and temperature.

Another purpose is to provide a machine tool and more particularly a milling machine in which structure suited for various of the purposes above mentioned, and for other purposes is combined in a manner to generally simplify and improve the construction and operation of the machine.

A further purpose is to generally simplify and improve the construction and operation of machine tools and particularly of milling machines, and further purposes and advantages will be apparent from this specification.

The

invention resides in the combination and arrangement of parts as herein illustrated, described, and claimed and in such modifications of the structure illustrated as may be equivalent to the claims.

Like reference characters indicate like parts throughout this specification and the various views of the drawings, of which:

Fig.

1 is a right-side elevation of a milling machine involving the invention.

Fig. chine.

2 is a front elevation of the same ma- 3 to the right or left in Fig. 2.

Fig. 3 is a front elevation of a portion of the machine enlarged.

Fig. 4 is a section on the line 4-4 of Fig. 3. Fig. 5 is a section on the line 55 of Fig. 3. Fig. 6 is a section on the line 6--6 of Fig. 3. Fig. 6a is a continuation of Fig. 6 but on the line 6a-6a of Fig. 3.

Fig. 7 is a part section on the line l-l of Fig. 6.

Fig. 8 is a section on the 8-8 of Figs. 10

Fig. 9 is a schematic sectional view in the nature of a development showing the hydraulic circuits.

Fig. 10 is a section on the line ill-l0 of 5 Fig. 8.

Fig. 11 is an enlarged view of certain valve sleeves shown in Fig. 8.

Fig. 12 is a sectional view of the valve sleeves shown in Figs. 8 and 11 on the line I2l2 of 20 Fig. 11.

Fig. 13 is a development of the openings in the valve sleeves.

. thereon a knee 2 carrying a saddle 3 slidably adjustable relative to column I and supporting a work table 4 horizontally slidable on saddle A tool spindle 5 is rotatably supported in column I above table 4 for which transmission mechanism is provided as follows:

A pulley G is fixed on a sleeve I journaled in I a suitable bearing 8 in a wall of column I and 45 drives a shaft 9 through a friction clutch, generally denoted by reference numeral I0, and shaft 9 drives a shaft ll through a rate changer, generally denoted by numeral l2. Shaft II in turn drives spindle 5 by means of a gear I3 50 fixed with the spindle and meshing with a pin-, ion l4 fixed with shaft ll.

The clutch I0 includes an outer member l5 fixed with sleeve 1 and having a bore for the reception of an extension I 6 of shaft 9, exten- 55 sion l6 being journaled in the bore of sleeve 1 whereby sleeve 1 and member l5 may freely rotate relative to shaft 9, but shaft 9 will be held in axial alignment with sleeve 1. A member l1 slidably keyed with shaft 9 is adapted to frictionally engage a suitable recess in member l5 and may be moved into and out of engagement therewith by means of a hand lever |8 fixed on a shaft l9 journaled in a suitable bearing in column and having also fixed therewith a. lever 28 adapted to operate a lever 2|, fixed on a shaft 22 journaled in suitable bearings in column I, by means of a rod 23 pivoted at its ends to the respective levers. Shaft 22 has fixed thereon a lever 24 carrying at its end a. portion 25 engaging a spool 26 fixed with member |1 whereby motion of lever l8 to the right or left in Fig. 1 will cause member H to move into and out of engagement respectively with member I5 and accordingly stop or start rotation of shaft 9. a The rate changer |2 comprises gears 21, 28, 29 fixed together and slidably keyed on shaft 9 meshing one at a time with gears 30, 3| 32 fixed with shaft Gears 21, 28, 29 may be shifted manually by means of a hand lever 33 fixed on a shaft 34 journaled in column and having fixed on its inner end a lever 35. Lever 35 has a fork member 36 pivoted thereto and engaging the side edges of gear 28 whereby a swinging movement of lever 35 will cause sliding movement of gears 21, 28, 29 but without interfering with rotary motion of the gears.

Transmission mechanisms is provided for movement of table 4 including a feed pump of relatively small displacement, generally denoted by numeral 31, Figs. 8, 9, and 10, and-a rapid traverse pump of relatively large displacement,

generally denoted by the numeral 38, Figs. 9,

10, and 14.

Pump 31 may be of any suitable type, but in this case consists of gears 39 and 48 meshed together within a substantially closed housing 4|, as shown particularly the housing providing an inlet port 42 and an outlet port 43. Pump 31 is connected to be driven from the spindle transmission at a point between clutch l8 and the rate changer |2 through a train consisting of a gear 44, Figs.

1 and 9, fixed on shaft 9 and driving a gear 45 fixed on a shaft 46 through idlers 41 and 48, Fig. 2. An extensible universal joint shaft of wellknown form, generally denoted by numeral 49, connects shaft 46 to drive a pump shaft 50, Figs. 8 and 9, through a shaft 5|, Fig. 9, journaled in a member 52 fixed with saddle 3 and constituting a means for supporting the pumps and their associated mechanism. Shaft 5| drives a vertical shaft 53 through bevel gears 54 and 55 fixed with the respective shafts and shaft 53 drives shaft 58 through bevel gears 56 and 51 fixed with the respective shafts, the joint shaft providing a connection between shafts 46 and 5| in any position of the movements of knee 2 and saddle 3.

Pump 38 may be of any suitable form, but in this case consists of gears 58 and 59, Figs. 9, l0, and 14, meshed together within a substantially closed housing 68 providing an inlet port 6| and an outlet port 62. Gear 58 is fixed on a shaft 63 and gear 59 is supported for rotation on a sleeve 64, Figs. 9 and 14, through which passes shaft 58 to reach pump 31. Shaft 63 is driven from the spindle transmission at a point between the clutch Ill and pulley 6 by means of in Figs. 8, 9, and 10,

a train including a gear 65, Figs. 1 and 9, fixed on sleeve 1, a gear 66 fixed on a shaft 61 and idler gear 68 connecting the gears 65 and 66, the shafts 61 and 69 being connected by means of an extensible universal joint shaft of wellknown form, generally denoted by numeral 10, whereby shaft 61 may drive shaft 69 in any position of knee 2 and saddle 3. Shaft 69 drives a vertical shaft 1| through bevel gears 12 and 13 fixed with the respective shafts and shaft 1| drives shaft 63 through bevel gears 14 and 15 fixed with the respective shafts.

The pumps 31 and 38 are positioned within a hollow housing or casing, generally denoted by numeral 16, and providing a fluid reservoir with which the inlet ports 42 and 6| communicate. The inlet port 42 of the feed pump 31 communicates with the reservoir through a feed regulating throttle, generally denoted by numeral 11, Figs. 8, 9, ll, 12, and 13, and which will be described in detail below.

The output of eachof the pumps 31 and 38 is lead through passages 18 and 19 respectively to a rate change valve, generally denoted by numeral 80, Figs. 5, 8, and 9, which includes a rotatable stem 8|, Figs. 5, 8, 9, and 21 to 24 inclusive, having cut-away portions 82, the remaining portion of stem 8| being beveled as shown at 83, Fig. 21. From rate change valve 88 the fluid passes through suitable channels to a reverser valve, generally denoted by numeral 84, Figs. 5, 6, 8, 9 and 15 to 20 inclusive, and on to a fiuid motor, generally denoted by numeral 85.

Outlet port 43 of fluid pump 31 communicates with rate change valve adjacent a lower portion of valve stem 8| through passage 18, while outlet port 19 of rapid traverse pump 38 communicates with rate change valve 80 adjacent an upper portion of valve stem 8|. A port 86, Figs. 8 and 21 to 24 inclusive communicates from rate change valve 88 to reverser valve 84 from a point to one side of valve stem 8| and an exhaust port 81 communicates freely with reservoir 16 from a point adjacent the other side of valve stem 8|. Thus port 86 may be supplied from either pump 31 or 38, according to the position of valve stem 8|, as will be apparent from Figs. 21 to 24 inclusive, the alternate pump discharging freely through port 81 and consuming substantially no power.

Port 86 leads to reverser valve 84 which includes a rotatable stem 88 having cut-away portions as particularly shown in Figs. 15, 1'1, and 19, and from reverser valve 84 through suitable channels to the one or the other end of a cylinder 89, Figs. 2, 5, and 9, constituting a part of fiuid motor 85, fixed with saddle 3 and having a piston head 90 fixed with a piston rod 9| which is fixed at end 92 for movement with table 4, the communicating channels being as follows:

Port 86 communicates with ports 93 and 94, Figs. 8, 9, 15, 1'1, and 19, opening into a bore 95 of reverser valve 84 adjacent upper and lower portions of valve stem 88 respectively. Adjacent the upper portion of valve stem 88 are ports 96 and 91, Figs. 15, 17, and 19, communieating with passages 98 and 99 respectively, Fig. 9, communicating with end portions of cylinder 89 on opposite sides of piston 90. Adjacent the upper portion of valve stem 86 there is also a port H10, Figs. 9, 15, 1'1, and 19, leading to reservoir 16 through throttle devices to be described presently. Adjacent the lower portion of valve stem 68 there is a port IOI, Figs. 9, 16, 18, and

- 20, communicating freely with reservoir I6.

The arrangement is such that when valve stem 88 is in the position shown in Figs. 15 and 16, the pressure port 86 communicates with port -IOI through ports 94 and a port I02 formed in valve stem 88, the ports 96 and 91 leading to the cylinder being closed. When the valve stem 68 is in the position shown in Figs. 17 and 18, the pressure port 93 communicates with the left end, Figs. 2 and 9, of the cylinder 09 through port 96 and channel 98, valve port I02 being closed as shown in Fig. 18, the piston 90 and table 4 being thereby forced to the right in Figs. 2 and 9. Fluid in the right-hand end of the cylinder is then forced out through channel 99 and valve port 91 into port I00 and thence to reservoir I6. M

When the valve stem 88 is in the position shown in Figs; 19 and 20, pressure port 93 communicates with the right-hand end, Figs. 2 and 9, of cylinder 69 through ports 93, 91 and channel 99, thereby moving the piston and table to the left, fluid from the left-hand end of the cylinder being forced to reservoir I6 through channel 98 and valve ports 96 and I00.

Port I00 communicates with reservoir 16 through a spring valve or throttle, generally denoted by numeral I03, Figs. 6 and 9, and another valve or throttle, generally denoted by numeral I04. Valve I04 provides a ball I05 pressed by a spring I06 whereby to maintain a predetermined back pressure against the escape of fluid ing fixed thereon a piston head IIO movable in a cylinder III. A pipe or channel II2 com-' municates from pressure channel 93 to the upper end of cylinder III whereby to oppose spring I09 by means of fluid under pressure derived from channel 93. The area of piston H0 is such that when a predetermined high pressure exists inchannel 93, plunger I01 will be moved down against the pressure of spring I09 to a position to bring an opening H3 in plunger I01 into a position relative to outlet channel I00 such that the outlet channel is practically unrestricted, but if the pressure in channel 93 falls below a predetermined point or to zero, as it would for instance in case' the cutter should catch the work and tend to pull table 4 along at a rate faster than that for which the feed mechanismis adjusted, spring I 09 will move plunger I01 to substantially close the outlet channel I00 and thereby check such undesirable overrunning movement. For intermediate pressures the outlet restriction varies. The mechanism provides an automatic restriction of the motor outlet with a variety of attendant advantages more fully discussed in a preceding application, Serial 321,250, filed November 22, 1928.

The means for adjusting the rate of feed of table 4 comprises throttle 11 located in the intake channel of feed pump 31. As .shown in Figs. 8 and 11 to 13 inclusive, throttle 11 consists of sleeves H4, H5, and H6 movable relatively to each other and to a bore II'I formed in member 52 and communicating with port 42. Sleeve H6 is rotatably fitted in bore I" so as to be substantially fluid tight and has a port H8 which may register partially or wholly with an intakeport II9 formed in member 52 and intersecting bore III. Sleeve II6 may be manually rotated by means of a hand control I20,

Fig. 4, fixed with a shaft I2I journaled in saddle 3 and actuating sleeve II6 through a bevel gear I22 fixed with shaft I2I and meshing with a bevel gear I23 fixed with sleeve II6. Hand control I20 is provided with a pointer I24 for indicating the adjustment of the parts against a scale I25, the proportions being such that the degree of registration of ports I I8 and H9 will admit suflicient fluid to pump 3'I to produce substantially the rate of table feed indicated by 10 pointer I24.

With any type of throttle control of rate or 'volume difliculty may be experienced by reason sleeve H5 will cause a change in the effective 25 area of the opening and accordingly in the fluid flow.

Sleeve H5 is prevented from axially moving relative to sleeve I I6 by means of a shoulder I2I fixed with sleeve H5 and bearing against gear 30 I23 and a set screw I26 fixed with a portion of member 52, as shown in Fig. 8. At the opposite end from portion I26 sleeve H5 is made solid and has gear teeth formed thereon engaging with rack teeth formed on a plunger 35 I29, Figs. 4, 8, and 9, freely slidable in a bore formed in member 52. Plunger I29 is caused to move in response to variations in temperature by the action of a temperature responsive element which may be of any suitable type but 40 in the present instance consists of a bi-metallic spring I30 which is formed of a composite strip of two metals of different coeflicients of expansion, wound into a helix, the helix being then wound into a larger helix. Such a spring will 45 elongate considerably under a slight rise of temperature. Spring I30 is located in a protesting casing I3 I open on its under side as shown and fastened at one end to plunger I29 and at the other end to 'a block I32 which is slid- 50 able in the casing and maybe longitudinally adjusted by means of a bolt I33 rotatably fixed with block I32 and threaded through a plug I 34'fixed with casing I3I. A look nut or other suitable means may be provided to maintain the 55 adjustment of bolt I33.

It is to be understood that various types of temperature responsive elements are adaptable to applicant's purposes, many of which are well known, and that applicant contemplates the use 60 of any of these which maybe found suitable, the structure disclosed being merely illustrative, and not to be taken as limiting the invention.

Changes in the length of spring I30 will cause sliding movement of plunger I29 and accordingly (:5 rotary movement of sleeve H5. The angle of end portion I26 is such that rotary movement of sleeve H5 in the direction caused by expansion of spring I30 will reduce the effective area of the intake port 9, while such movement in the direction caused bycontraction of spring I30 will increase the effective area of the intake opening, the proportions of the various parts being such that the volume of working fluid admitted for any given setting of sleeve I I6 will remain substantially constant, regardless of the changes in consistency of the fluid.

It is realized that there will be a certain amount of leakage of fluid past piston 90 and also from the high to the low pressure side of pump 31. The latter is without effect since pump 31 has a capacity considerably in excess of the maximum capacity of throttle I1 and any fluid leaking by the impellers is simply added to that coming through throttle 11 into port 42 and repumped, so that the volume of fluid forced through passage I8 is equal to'the volume coming through throttle 11 at all times. The leakage past piston 90, however, will result in a slightly slower travel of piston 90 and table 4 than would be the case if there were no leakage. Furthermore, this leakage will vary inversely as the viscosity of the fluid and it will accordingly counteract to a certain extent the tendency of the table to run faster upon an increase in temperature of the working fluid which would be present were it not for the action of sleeve H5. It is accordingly contemplated that the action of sleeve H5 may be made to be such as not necessarily to maintain a constant flow of fluid through throttle 11, but to allow-just sufilcient change to compensate for the changed leakage past piston 90 caused by the change in viscosity of the fluid, and thereby maintain the rate of table 4 constant for any given pressure condition.

The leakage will also vary in accordance with the variations in pressure difference between the high and the low pressure sides of the system. Such variations in pressure may arise from a variety of causes and the leakage variations resulting therefrom will tend to cause undesirable variations in the speed of table travel, for any given setting of rate control throttle 11. This objectionable action is likely to develop in any hydraulic circuit, independently of the type of rate controller used. In the present instance it is counteracted by an automatic pressure responsive movement to sleeve I I4 which, as shown in Fig. 8, is fitted for axial sliding movement in sleeve I I6 and a reduced portion of bore I I1, and projects into and partly closes the throttle opening H8 in sleeve IIG. Sleeve H4 is actuated in response to the pressure obtaining in passage 86 and accordingly in cylinder 89 by means of a .plunger I35 operating in a cylinder I35, receiving fluid from passage 86 through a duct I31. Movement of plunger I35 is opposed by a spring I38 and its motion is transmitted to sleeve II4 by means of a shaft I39, Fig. 4, journaled in a bore in member 52 and having a gear I40 fixed therewith at one end and engaging rack teeth formed on plunger I35. Shaft I39 has a gear I4I Fig. 8, fixed therewith on the other end and engaging rack teeth formed on sleeve I I4.

Thus upon increase of pressure in cylinder 89 and port 86, plunger I35 is forced to the right in Fig. 8 against the resistance of spring I38, thereby, through rotation of shaft I39, moving sleeve II4 to the left. This movement increases the effective opening of throttle -'I'I and admits sufiicient extra fluid to port 42, to compensate for the increased leakage resulting from the increased pressure, and the parts are so proportioned that the extra fluid maintains the rate of travel of table 4 in spite of the increased leakage.

Conversely, if the pressure in cylinder 89 falls, the leakage will tend to decrease and table 4 will tend to travel faster, but this effect will also be counteracted by sleeve II 4, since spring I 38 will overcome the diminished pressure in cylinder I36 and forceplunger I35 to the left in Fig. 8, thereby moving sleeve II4 to the right and reducing the effective opening of throttle I1. The amount of fluid pumped will thus be reduced correspondingly with the decrease in fluid leakage, and the parts are proportioned so that the rate of table travel will be kept substantially constant in spite of the change in leakage.

The action of sleeves H4 and H5 is independent of that of sleeve H6 and the construction is such that the compensating devices are properly effective whatever the position of sleeve H6, 50

that compensation for temperature differences and pressure differences takes place automatically regardless of the position of sleeve I I6, and the travel of table 4 is always substantially the same for any given setting of the feed rate controller.

In order to guard against damage to the transmission from overloads, or the like, a relief valve I42 is provided, communicating with port 18, as shown in Fig. 8. The valve comprises a ball I43 pressed against a seat I44 in a passage I45 leading from passage I8 by a spring I46 suitably pressed against the ball as by a hollow plug I41,

the spring being of sufiicient strength to seat ball I43 against all normal load pressures, but yielding in the event of excessive pressure to allow escape of fluid from port I8. A similar relief ,valve I48 is provided communicating with port I9 for relief of excessive pressure against the rapid traverse pump 38, the spring in this valve being sufliciently flexible to relieve any pressure substantially in excess of the normal rapid traverse pressure.

Rate change valve 80 and reverser valve 84 may be operated by any suitable means, but in the present case are operable either by hand or automatically through table dogs, as shown in Figs. 1, 2, 3, 5, and 6a. Thus rate change valve 80, Fig. 5, may be set to cause either feed or rapid traverse motion of table 4 by means of a hand lever I49 fixed with a shaft I50 journaled in a member I5I fixed with saddle 3 and in a bearing I52, and driving a vertical shaft I53 journaled in member 52 through bevel gears I54 and I55 fixed with the respective shafts. Shaft I53 has a bevel gear I56 fixed therewith and meshing with a bevel gear I51 fixed with valve stem 8I, whereby -movement of lever I40 will cause rotation of stem 8|. Valve 80 may also be moved by means of table dogs, as follows:

Shaft I50 has rlxed thereon a gear I58 meshing with rack teeth formed in plungers I59 and I60 vertically slidable in saddle 3 and engaging gear I58 on. opposite sides of the axis thereof, whereby rotary movement of gear I58 will raise one plunger and lower the other. Plungers I59 and I60 have upper angular cam surfaces adapted to contact with dogs such as I6I and I62 respectively, fixed with table 4 at desired points by means of bolts I63 and I64 engaging a T'-slot I65.

Plungers I59 and I60 are in different vertical planes perpendicular to shaft I50 as shown in Fig. 5, whereby a dog may contact one and not the other. Thus it is possible to provide as many of dogs I6I and I62 as desired, so that change from feed rate to rapid traverse rate may be automatically effected at as many points in the travel of table 4 as desired, the dogs of the type of I6I contacting plunger I59 only and those of the type of I62 contacting plunger I60 only, as

position against accidental displacement and to aozaaez shown in Fig. 5. If it is desired to effect operation of one or the other of plungers I59 and I60 upon one stroke of table 4 and not to effect such operation during the return stroke thereof, dogs I6I or I62 numerous examples are well known and accordingly not described here. Thus contact of dog I62, Fig. 3, with plunger I60 will depress the plunger and rotate gear I58 in a clockwise direction, thereby shifting valve from the feed position, shown in Fig. 21, to the rapid traverse position shown in Fig. 24, and raising plunger I59 into the'path of dog I6I.

- The beveled portions of stem 8I shown in Figs. 21 to 24 inclusive are for the purpose of. insuring that there will be no point in the movement of valve 80 where neither of ports 18 nor 19 will be in communication with port 86. If such a condition were permitted to occur during the shifting of the valve, it will be apparent that the table would stop and the shifting would not be completed, since there would be a failure of the fluid supply to motor 85. In the present situa-, tion, as shown in' Figs. 21 and 22, during movement of the valve, fluid from one pump is not cut off until after fluid begins to be admitted from the other pump. Thus the table continues to move and shift valve 80 until it takes the position shown in Fig. 24 when table 4 moves at the new rate determined by the capacity of the rapid traverse pump now delivering fluid to motor 85.

Fig. 22 shows the valve 80 in position midway between feed and rapid traverse positions wherein, owing to the beveled form of valve member 8I, fluid is flowing to motor through port 86 from both of ports 18 and 19.

At the instant the valve stem 8I is passing through the position shown in Fig. 23, port 18 is blocked and fluid coming from pump 31 escapes through relief valve I42. Table 4 will continue to move, however, since port 19 leading from rapid traverse pump 38 is still open and continued movement of table 4 will shift valve stem 8| to the position shown in Fig. 24.

A similar course of events will take place when dog I6I contacts plunger I59 and valve stem 8I will be shifted from the position shown in Fig. 24 to that shown in Fig. 21 and the rate of table 4 will be changed from rapid traverse to feed.

In order to maintain valve 80 inits shifted cause a rapid and positive movement thereof when shifted by the dogs, a cam member, I66, Figs. 3 and 5, is fixed with shaft I50 and has notches for engagement with a plunger I61 pressed against member I66 by a spring I68.

Reverser valve 84 may be hand operated by means of a lever I69, Figs. 2, 3, 6a, and 9, fixed with a shaft I10 journaled in a bushing I which is in turn journaled in a member I12 fixed with a saddle 3. Shaft I 10 drives a shaft I13 journaled in saddle 3 through a sector I14 and a gear I15 flxed with the respective shafts, shaft I13 actuating valve stem 88 through a bevel gear I16 fixed on shaft I13 and meshingwith a bevel gear I11 fixed with valve stem 88,

whereby movement of handle I69 to the right' in Fig. 3 will turn valve stem 88 into the position shown in Figs. 17 and 18, whereby fluid will be admitted through port 96 and passage 98 to the left end of cylinder 89, causing piston '90 and table 4 to move to the right. Con- -versely, movement of handle I69 to the left will} cause movement of table 4 to the left, as will be understood.

may be of the latch type ofwhichv cam I81 is also fixed with sleeve I10 and cooperates with a plunger I88 slidable in a bore in saddle 3 and pressed against cam I81 by a spring I89. Cam I81 has a central notch I 15 cooperating with plunger I 88 for yieldably holding the parts in a substantially central position and has other notches I9I, I92, located at. either side of notch I90, adapted when cam I81 is displaced from such central position to cooperate 20 with plunger I88 to move cam I81 and bushing "I to the limit of its travel in the direction in which it is initially displaced.

Thus, if hand lever I69 is moved to the left in Fig. 3 and no lost motion is provided be- 25 tween lug I 86 and screws I84 and I85, bushing "I will be rotated in a counterclockwise direction, cam I81 will be moved so that plunger I88 will drop into notch I9I, plunger I80 will be raised into the path of a dog I93 fixed with 30 table 4 at a predetermined point by means of a bolt I94 engaging T-slot I65 and valve 84 will. be moved into the position shown in Fig. 19, opening port 91 to fluid pressure and causing table 4 to move to the left. Dog I 93 will con- 35 tact plunger I80 after a certain amount of table travel and depress the same, thereby rotating gear I'18, bushing "I, and shaft I10 in a clockwise'direction and moving valve stem 88 towards the position shown in Fig. 15, such movement causing cam I81 to force plunger I88 out of notch I9I. When the parts have moved sufllciently, plunger I88 will drop into notch I90 and stem 88 will reach the position shown in Fig. 15 and table 4 will stop. 45

However, if lost motion is provided between lug I86 and screw I84, cam I81 will reach a central position before valve stem 88. Table 4 will accordingly continue to move, since valve 84 will not have reached the position shown in 50 Fig. 15, port 91 will still be open, and dog I93 will cause cam I81 to move beyond a central position, whereupon plunger I88 will be caused by spring I89 to drop into notch I92, thereby forcing cam I81, bushing HI, and shaft I10 55 to rotate in a clockwise direction, moving valve stem 88 to the position shown in Fig. 17 and causing table 4 to move to the right.

At the same time, plunger I19 will be raised into the path of a dog I95 fixed with table 4 60 at a predetermined point by means of a bolt I96 engaging T-slot I65. If lost motion is provided between lug I86 and screw I85, the table will stop, as above outlined, upon contact of dog I95 with plunger I19, while if such lost 65 motion is provided, the table will reverse at this also be accomplished automatically by means of table dogs.

It is to be understood that the dimensions and proportions of the parts shown in the drawings are to a large extent conventional and should be considered as subject to modification within the range of equivalents indicated in the annexed claims to the extent dictated by considerations of convenience and practicability.

What is claimed is:

1. In a machine tool, the combination of a movable member, a transmission for actuating said member including a fluid operable motor, a pump and a fluid circulating system including a channel between said pump and motor containing fluid under pressure; and control means for said transmission including a rate control throttling means shiftable for varying the rate of motor movement, a temperature responsive device, and mechanism for shifting said throttling means in accordance with changes in said temperature responsive device whereby to maintain said rate substantially constant in spite of variations in fluid temperature.

2. In a machine tool, the combination of a movable member, a transmission for actuating said member including a fluid operable motor, a pump and a fluid circulating system including a channel between said pump and motor containing fluid under pressure; and control means for said transmission including a throttling device adjustable to change the flow of fluid to said pump whereby to change the rate of fluid movement into said channel, a temperature responsive device, and mechanism connecting said throttling device to be shifted in accordance with changes in said temperature responsive device, whereby to maintain the rate of said motor substantially constant in spite of variations in fluid temperature. r

3. In a milling machine, the combination of a rotatable tool spindle, a support for said spindle, a work support, one of said supports being movable relative to the other support in a direction transverse to the axis of said tool spindle, a power train for rotation of said spindle including a power source and a spindle rate changer, a transmission for movement of said movable support including -a pump actuated from said power source to exclude said rate changer, a fluid operable motor and a fluid passage connecting said pump and motor, a reservoir for fluid, a channel connecting said reservoir and the inlet port of said pump, a throttling device associated with said channel and adjustable to change the volume of fluid delivered to said pump whereby to change. the rate of fluid movement into said channel, a temperature responsive device and mechanism connecting said throttling device for movement in accordance with changes in said temperature responsive device, whereby to maintain the rate of said motor substantially constant in spite of variations in fluid temperature.

4. In a milling machine, the combination of a rotatable tool spindle, a support for said spindle, a work support, one of said supports being mov- 'able relative to the other support in a direction transverse to the axis of said tool spindle, a power train for rotation of said spindle including a power source and a spindle rat: changer, a transmission for movement of said movable support and providing a fluid operable portion including a pump actuated from said power source to fexclude said spindle rate changer, a

fluid operable motor and a fluid passage connecting said pump and said motor, and control means for said transmission including a rate control throttle device associated with said fluid operable portion and adjustable to change the rate of actuation of said motor, a temperature responsive device and mechanism connecting said throttle device to be shifted in accordance with changes in said temperature responsive device, whereby to maintain said motor rate in 10 spite of variations in fluid temperature.

5. In a milling machine, the combination of a rotatable tool spindle, a support for said spindle,

a work support, one of said supports being movable relative to the other support in a direction transverse to the axis of said tool spindle, a power train for rotation of said spindle including a power source, a clutch and a spindle rate changer, a transmission for movement of said movable support including a pump actuated from said power source through said clutch to exclude said spindle rate changer, a fluid operable motor and a fluid passage connecting said pump and said motor, a reservoir containing working fluid,

a channel connecting said reservoir and the inlet port of said pump; and rate control means for said transmission including a throttle device shiftable to change the area of the effective fluid passage therethrough, a temperature responsive} device, and means operative to shift said throttle device in accordance with changes in said temperature responsive device.

6. In a machine tool, the combination of a movable member, a transmission therefor including a fluid operable motor, fluid supply means operable for effecting different rates of said motor including a relatively slow feed rate and a quick traverse rate, and a pressure channel connectible between said supply means and said motor; and control mechanism for said transmission including a first controller shiftable for alternative actuation of said motor at one or the other of said rates, and other control means including a throttle device shiftable independently of said first controller to change the volume of fluid delivery to said channel, a temperature responsive device associated with said transmission, and means connecting said throttle device to be shifted in accordance with changes in said temperature responsive device, whereby to maintain said feed rate of motor actuation substantially constant in spite of changes in temperature of the transmission fluid.

'I. In a milling machine, the combination of a rotatable tool spindle, a support for said spindle, a work support, one of said supports being movable relative to the other in a direction transverse to the axis of said tool spindle, a power train for rotation of said spindle including a power source and a spindle rate changer, a transmission for said work support including a fluid operable motor, pump means driving from said power source to exclude said spindle rate changer and operable for efiecting different rates of said motor including a feed rate and a rapid traverse 5 .rate, and a pressure channel connectible between said pump means and said motor, and control mechanism for said transmission including a first controller shiftable for alternative actuation of said motor at one or the other of said rates, and other control means including a throttle device shiftable to change the volume of fluid delivery to said channel, a temperature responsive device associated with said transmission, and means connecting said throttle device to be shifted in accordance with changes in sai temperature responsive device.

8. In a milling machine, the combination of a. rotatable tool spindle, a support for said spindle, a work support, one of said supports being movable in a direction transverse to the axis of said tool spindle, a power train for said tool spindle including a power source, and a spindle rate changer, a transmission of movement of said movable support including a feed rate pump and a quick traverse rate pump, each of said pumps being connected to be driven from said power source exclusive of said spindle rate changer, a

' fluid operable motor, and a pressure channel connectible to receive fluid from each of said pumps for said motor; and control means for said transmission including a first controller'for connecting said motor to be operated exclusively from said feed pump or alternatively at a quick traverse rate, a throttledevice shiftable for changing the rate of fluid delivery from said feed pump to said channel, a temperature responsive device associated with said transmission, and means connecting said throttle device to be shifted in accordance with changes in said temperature responsive device.

9. In a milling machine, the combination of a rotatable tool spindle, a support therefor, a work support, one of said supports being movable in a path transverse to the axis of said spindle, a.

power train for the rotation of said spindle including a power source and a spindle rate changer, a transmission'for movement of said movable support including a feed rate pump and a quick traverse rate pump, both said pumps being driven from said power source to exclude said spindle rate changer, a fluid operable motor adapted to actuate said support, and a pressure channel connectible to receive fluid from each of said pumps for said motor, a fluid reservoir, channels for supplying fluid from said reservoir to said pumps including an inlet channel portion individual to said feed rate pump; and control means for said transmission including a first controller operable for connecting said motor to be operated exclusively from said feed pump or alternatively at a quick traverse rate,-a,throttle device associated with said feed pump inlet channel portion and shiftable for changing the rate of flow of fluid to said feed rate pump whereby. to change the rate of fluid delivery from said feed pump to said pressure channel, a temperature responsive device, and means connecting said tln'ottle device to be shifted in accordance with changes in said temperature responsive device.

10. In a machine tool, the combinationv of a movable member, a transmission therefor including a fluid operable motor, fluid supply means operable for effecting different rates of said motor including a series of relatively slow feed rates and a' quick traverse rate, and a pressure channel connectible between said fluid supply means and said motor, and control mechanism for said transmission including a first controller shiftable for actuation of said fluid motor alternatively at one or the other of said feed or quick traverse rates, a second controller shiftable independently of said first controller to various positionseach pre-selective of one of said series of feed rates tobe effected upon subsequent shifting of said first controller, a thirdcontrol means shiftable independently of each of said controllers for changing the rate of fluid delivery to said pressure channel during feed rate actuation of said motor, a temperature responsive device and means connecting said third control means to be shifted in accordance with variations in said temperature responsive device.

11. In a machine tool, the combination of a movable support, a transmission for movement of said support including a fluid operable motor, a feed rate pump, a quick traverse rate pump, and

a pressure channel connectible between each of said pumps and said motor, and control mecha-.

fluid delivery to said pressure channel during actuation of said motor from said feed pump, a temperature responsive device, and means connecting said third control means to be shifted in accordance with temperature changes in said temperature responsive device.

12. In a machine tool, the combination of a tool support, a support for said spindle, a work support, one of said supports being movable with relation to the other support, a transmission for movement of said movable support including a fluid operable motor, pump means and a pressure channel connecting said pump means and said motor; and control mechanism for said transmission including a first controller adiustable for changing the flow of fluid from said pump means to said pressure channel whereby to approximately predetermine a series of different rates of said motor, a second controller adjustable independently of said first controller for changing'the flow of fluid from said pump means to said pressure channel, a temperature responsive 'device, and means connecting raid second controller for adjustment in accordance with changes in said temperature responsive device and in a direction to increase the flow of fluid to said channel upon an increase-in temperature and vice versa.

13. Ina machine tool, the combination of a movable member, a transmission for actuating said member including a fluid operable motor, a pump having an inlet channel, and a pressure channel between said pump and motor and control mechanism for said transmission including a throttling device associated with said inlet channel and adjustable to change the flow of fluid to the inlet port of said pump, a pressure responsive device connected to be operated in accordance with variations in pressure within said pressure channel, and means connecting said throttling device for adjustment in accordance with changes in said pressure responsive device.

14. In a milling machine, the combination of av tool spindle, a support for said spindle, a work support, one of said supports being movable relative to the other support in a direction transverse to the axis of said tool spindle, a power train. for said spindle including a power source and a spindle rate changer, a transmission for movement of said movable support including a pump having an inlet channel and actuated from said power source exclusive of said spindle rate changer, a fluid operable motor and. a pressure passage connecting said pump and said motor, and control mechanism for said transmission including a throttle associated with said inlet channel and adjustable to change the rate of fluid delivery to said pump, a pressure responsive device connected to be operated in accordance with variations in pressure in said pressure channel, and means connecting said throttle for adjustment in accordance with changes in said pressure responsive device, and in a direction to increase the opening of said throttle when the pressure increases in said pressure channel and vice versa.

15. In a machine tool, the combination of a movable support, a transmission for movement of said support including a fluid operable motor, fluid supply means operable for effecting difierent rates of said motor including a relatively slow feed rate and a quick transverse rate, and a pressure channel between said supply means and said motor; and control mechanism for said transmission including a flrst controller shiftable for alternative actuation of said motor at the one or the other of said feed or quick traverse rates, a device determinative of the feed rate of operation of said motor, and other control means including a throttle shiftable independently of said first controller to change the volume of fluid delivery to said channel, a pressure responsive device connected to be operative in accordance with pressure changes within said channel, and a motion transmitting connection for shifting said throttle in accordance with changes in said pressure responsive device.

16. In a machine tool, the combination of a work support and a tool support, one of said supports being bodily movable, a tool actuating transmission including a rate changer and a power source, a transmission for movement of said movable support providing pump means including a feed rate pump, a quick traverse rate pump, both of said pumps being driven from said power source, exclusive of said rate changer, a fluid motor adapted to actuate said support, and a pressure channel connectible between each of said pumps and said motor, and control means for said transmission including a first controlleralternatively operable for connection of said pump means for effecting a feed rate or a quick traverse rate of said motor, other control means shiitable independently of said first controller for changing the rate of fluid flow from said pump means to said pressure channel, a pressure responsive device operable in accordance with changes in pressure within said pressure channel, and means connecting said other controller to be shifted in accordance with changes in said pressure responsive device.

17. In a machine tool, the combination of a tool support and a work support, one of said supports being bodily movable, a tool actuating transmission including a rate changer and a power source, a transmission for movement of said movable support including a fluid operable motor, a pump driven from said power source and a pressure channel, connected between said pump and said motor, and control means for said transmission including a throttle manually adjustable for changing the rate of flow of fluid to said motor, means adjustable to change the flow of fluid to said pressure channel, a pressure responsive device operative in accordance with variations in the fluid pressure in said channel, and a motion transmitting connection from said pressure responsive device to said adjustable means.

18. In a machine tool, the combination of a work support and a tool support, one of said supports being bodily movable, a tool actuating transmission including a rate changer and a power source, a transmission for movement of said movable support providing pump means including a feed rate pump capable of fluid delivery at rates suitable for feed movement of said support, a quick traverse rate pump capable of fluid delivery at rates suitable for rapid traverse movement of said support, a fluid operable motpr and a pressure channel connectible between each of said pumps and said motor; and control means for said transmission including valve means providing a first controller and associated with said channels for alternatively connecting said fluid motor to be operated exclusively from said feed pump or at a quick traverse rate, a feed rate change device providing a second controller and associated with said transmission and adjustable independently of said valve means for a variety of different feed rates of flow of fluid to said motor whereby to preselect a desired rate of actuation when said support is to be actuated at a feed rate, means providing a third controller adjustable independently of either other controller to change the volume of fluid delivered to said pressure channel, a pressure responsive device connected for operation in accordance with variations in fluid pressure in said pressure channel, and means connecting said pressure device for operation of said'third controller.

19. In a machine tool, the combination of a movable member, a transmission for actuating said member including a fluid operable motor, a pump, and a fluid system including a pressure channel connected between said pump and motor, control means for said transmission including throttle means shiftable for changing the rate of flow of fluid to said motor, temperature responsive means operable in accordance with changes in temperature in the fluid in said system, pressure responsive means operable in accordance with variations in fluid pressure within said channel, and connections simultaneously operable to shift said throttle means in accordance with changes in both said temperature responsive device and in said pressure responsive r device.

20. In a machine tool, the combination of a tool support, a work support, one of said supports being bodily movable, a transmission for movement of said movable support including a fluid operable motor, a source of fluid supply, and a pressure channel connectible between said supply source and motor, said supply source being alternatively operable for a relatively slow feed rate or for a quick traverse rate of said motor; and control means for said transmission including a controller alternatively operable to the eifect actuation of said motor at the one or the other of said rates, a device shiftable independently of said controller to change the rate of flow from said source to said pressure channel, another device operable in accordance with changes in some of the operating conditions of said machine, and means connecting said shiftable means to be shifted in accordance with changes in said other device.

21. A machine tool as specified in claim 20 including a second controller associated with said transmission and adjustable for a variety of feed rates of fluid flow from said source, said second controller being adjustable independently of said first controller and of each of said devices.

22. In a machine tool, the combination of a tool support, a work support,- one of said supports being movable relative to the other support,-a transmission for actuation of said movable support including a fluid operable motor, a fluid pump, a pressure channel connected for operation of said motor from said pump, a reservoir for working fluid, an inlet passageway for conducting fluid from said reservoir to said pump and an outlet passageway for conducting fluid from said motor to said reservoir; and said control means for said transmission including throttling means associated with said inlet passageway and providing a pluralityof portions independently adjustable for changing the rate of flow of fluid to said pump, temperature responsive means operative in accordance with temperature variations in said fluid, pressure responsive means operative in accordance with changes in fluid pressure within said pressure channel, manual means for adjustment of one of said portions, means for adjustment of another of said portions in accordance with changes in said temperature responsive device, means for adjustment of another of said portions in accordance with said pressure responsive device, a throttle device associated with said outlet passageway, another pressure responsive device operable in accordance with changes in the fluid pressure in said pressure channel, and means connecting the last mentioned throttle device to be operated in accordance with changes in the last mentioned pressure responsive device.

23. In a milling machine, the combination of a rotatable spindle, a spindle support, a work support, one of said supports being movable in a direction transverse to the axis of said spindle, a power train for said spindle including a power source and a spindle rate changer, a transmission for movement of said movable support and including a fluid operable motor, a fluid supply source including pump means driven from said power source to exclude said spindle rate chang-- er, a pressure channel connectible to connect said pump means to actuate said motor and an outlet passage from said motor, said supply source being in part adjustable for a variety of rates of fluid' supply, including a variety of relatively slow feed rates and a quick traverse rate; and control mechanism for said transmission including a first controller connected for adjustment of said adjustable portion for abruptly changing 10 from said quick traverse rate to a feed rate or vice versa, a manually operable second controller selectively adjustable independently of said first controller and connected for adjustment of said adjustable portion forv preselection of the .feed rate to be eflected by said first controller, a third controller connected for adjustment of said adjustable portion independently of said first and second controllers and for changing the volume of fluid delivered from said supply source to said so pressure channel, automatic means for operation of said third controller in accordance with changes in some of the operating conditions of said machine, restricting means associated with said outlet channel and adjustable for restricting the outlet of fluid therethrough, and a pressure responsive device operative in accordance with pressure changes in said pressure channel for shifting said restricting means.

24. In a machine tool, the combination of a movable member, a transmission for actuating said member including a fluid operable motor, a fluid supply source and a pressure channel; and control mechanism for said transmission including throttling means associated with said transmission and adjustable for establishing a predetermined rate of flow of fluid through said channel, a pressure responsive device connected to be operative from variations in fluid pressure within said channel, and means connecting said pressure responsive device for adjustment of said throttling means.

FRED A. PARSONS.

CERTIFICATE OF CZO RRECTION.

Patent No. 2,026,247. December El, 1935.

FRED A. PARSONS.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 7, first column, line 9, claim 8, for "of" first occurrence, read for; second column, line 28, claim 12, strike out the words and comma- "a support for said spindle, page-8, second column, line 61, claim 20, strike out the word "the"; page 9, first column, line 13, claim 22, strike out. the word "said" third occurrence; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office;

Signed and sealed this 5rd day of March, A. D. 1936.

Leslie Frazer (Seal) Acting Commissioner of Patents. 

